Safety arrangement

ABSTRACT

An air-bag unit ( 1 ) is adapted to be positioned on the floor pan of a vehicle in the foot-well, to be located beneath the feet of an occupant of the vehicle. The air-bag unit has an upper cover ( 8 ) located above an air-bag. On inflation of the air-bag the cover ( 8 ) is lifted from its initial position to an elevated position. The cover ( 8 ) comprises two sections ( 9, 10 ) inter-connected by a hinge-line ( 11 ). On inflation of the air-bag part of the cover ( 8 ) adjacent the hinge-line ( 11 ) is elevated so a greater extent than the portions of the cover which are remote from the hinge-line.

The present invention relates to a safety arrangement in the form of anair-bag arrangement, such as an air-bag arrangement mounted in a motorvehicle, or a load distribution element.

When a motor vehicle is involved in an impact, especially a frontimpact, the floor pan of the vehicle may be distorted. The distortion ofthe floor pan may be such that, if no protection is provided, a verysubstantial upward acceleration is applied to the feet of an occupant ofthe vehicle. This acceleration, although being an acceleration of a veryshort distance, may lead to substantial injuries to the feet or anklesof the occupant of the vehicle. Alternatively the floor pan of thevehicle may be distorted so that it intrudes substantially into thecabin of the motor vehicle.

It has been proposed to provide an air-bag or inflatable element locatedon the floor pan in the foot-well of a motor vehicle at a positionbeneath (or beneath and in front of) the feet of the occupant, theair-bag being adapted to be inflated as a consequence of an impact beingdetected, the inflated air-bag thus serving to lift the feet of theoccupant above the floor pan of the vehicle, providing a desirabledegree of protection.

It has been found that there is a particular risk of injuries arising ifthe forces applied on the feet and/or the ankles of an occupant of avehicle are very high, or are exerted on the feet or ankles at adisadvantageous angle. An ankle could be broken, for example, if thefoot is caused to rotate or bend in a specific direction relative to thelower leg. Thus, if an occupant has a typical position within a motorvehicle, an ankle could be broken if the foot rotates about a line thatis substantially aligned with the longitudinal axis of the vehicle.Injuries can also arise if the front part of the foot is bent upwardstoo much relative to the heel.

The present invention seeks to provide an improved air-bag arrangement.The present invention seeks to provide a load distribution elementwhich, in use, may obviate or reduce excessive eversion, inversionand/or dorsiflexion of a foot of an occupant of a motor vehicle in animpact situation.

According to one aspect of this invention there is provided an air-bagunit adapted to be positioned on the floor pan of a motor vehicle in thefoot-well, to be located beneath the feet of an occupant of the vehicle,the air-bag unit having an air-bag, and having an upper cover locatedabove the air-bag, the unit being such that on inflation of the air-bagthe cover is lifted from its initial position to an elevated position,the upper cover comprising two sections inter-connected by a hinge-line,the two sections being adapted such that on inflation of the air-bag thepart of the cover adjacent the hinge-line is elevated to a greaterextent than the portions of the cover which are remote from thehinge-line.

Preferably a pair of attachment elements are provided, the attachmentelements each being connected to one part of the upper cover and beingadapted to be connected to part of the motor vehicle to restrict upwardmovement of the said part of the cover.

Conveniently the cover comprises two sections, in the form of a firstsection adapted to be substantially horizontal and the second sectionadapted to be inclined, the air-bag lying under the second sectionpresenting a relatively large chamber, and the air-bag lying under firstsection presenting a plurality of separate chambers.

Advantageously each of the separate chambers is a tapering chamber.

Conveniently the inclined section of the cover is provided with a slitseparating the inclined section into two regions, one region beingadapted to lie on a foot-rest.

Advantageously the upper cover is provided with reinforcing means, thereinforcing means extending transversely of the cover.

Conveniently the cover is provided with reinforcing means to resistdeformation of the cover, there being more or stronger reinforcing meansin the region of the cover adapted to lie under the heel of an occupantof the vehicle than in other areas of the cover.

Preferably the reinforcing means extend transversely of the cover.

According to another aspect of this invention there is provided anair-bag unit adapted to be positioned on the floor pan of a motorvehicle in the foot-well, to be located beneath the feet of an occupantof the vehicle, the air-bag unit having an air-bag, and having an uppercover located above the air-bag, the unit being such that on inflationof the air-bag the upper cover is lifted from its initial position to anelevated position, the upper cover being provided with reinforcingmeans, the reinforcing means extending transversely of the cover toprovide the cover with substantial transverse rigidity.

According to a further aspect of this invention there is provided anair-bag unit adapted to be positioned on the floor pan of a motorvehicle in the foot-well, to be located beneath the feet of an occupantof the vehicle, the air-bag unit having an air-bag, the unit having anupper cover located above the air-bag, the unit being such that oninflation of the air-bag the upper cover is lifted from its initialposition to an elevated position, the upper cover being provided withreinforcing means to resist deformation of the cover, there being moreor stronger reinforcing means in the region of the cover adapted to lieunder the heel of an occupant of the vehicle than in other areas of thecover.

In the embodiments of the invention the reinforcing means may comprisethickened portions of the cover or, alternatively, may comprise integralelements of reinforcing material located within the cover. If the coveris moulded of plastics material, the reinforcing elements may be mouldedinto the cover.

The air-bag may be secured to the cover by adhesive or, alternatively,the cover is provided with integrally formed tongues, the air-bag beingconnected to the cover by means of elements provided on the air-bagwhich engage the said tongues.

In a preferred embodiment of the invention the cover forms part of ahousing that contains the air-bag.

In an alternative embodiment the cover rests on the air-bag.

Conveniently the air-bag is of metal.

According to this invention there is provided a load distributionclement to be mounted in a vehicle beneath at least one foot of anoccupant of the vehicle the element comprising a plate, the plate havinga first region of a predetermined strength and at least one furtherregion of a greater strength, the region of greater strength comprisingat least a first area to be located beneath a predetermined part of saidone foot. Preferably the said part of the foot is the heel of the foot.

The strength of the plate is equivalent to the stiffness of the plateand provides resistance against bending. The resistance against bendingmay be variable within the region of greater strength. The strength ofthe plate is such that the plate is resistant to bending in a directiontransverse to the longitudinal axis of the vehicle in which the elementis to be mounted.

Preferably said first area is dimensioned to be located beneath theheels of two feet of the occupant.

Conveniently the further region incorporates a second area which extendsadjacent one edge of the element to be located under one side of saidone foot.

Alternatively the further region incorporates two further areas whichextend adjacent two opposed sides of the element to lie under side partsof said two feet.

In one embodiment the element is substantially rectangular and thefurther region incorporates one area which extends across the elementwhich is spaced from said first area.

Conveniently the element includes at least one relatively weak areawhich has a strength which is less than said predetermined strength.

In one embodiment the relatively weak area is adjacent the second areato be located under the other side of said foot.

In another embodiment there are two said relatively weak areas locatedrespectively adjacent said two further areas to lie under the other sideparts of said feet.

In one example of the invention the element is provided with padding tobe located between the element and the floor of a vehicle. However, in apreferred embodiment the element is provided with an air-bag to belocated between the element and the floor of a vehicle. The element mayform part of the upper cover of a housing containing the air-bag. Thehousing may be a damp-proof scaled housing.

Conveniently the element is connected to the rest of the upper cover bya hinge-line.

In order that the invention may be more readily understood, and so thatfurther features thereof may be appreciated, the invention will now bedescribed, by way of example, with reference to the accompanyingdrawings in which:

FIG. 1 illustrates an air-bag arrangement in accordance with theinvention, before inflation thereof,

FIG. 2 shows the air-bag arrangement of FIG. 1 when inflated,

FIG. 3 is an enlarged sectional side view taken on the line II—II ofFIG. 5 showing thickening portions that reinforce part of the cover ofthe air-bag arrangement as shown in FIGS. 1 and 2,

FIG. 4 is a view corresponding to FIG. 3 showing an alternativeembodiment of the invention,

FIG. 5 is a view of the under-side of the cover of the air-bagarrangement as shown in FIGS. 1 and 2,

FIG. 6 is a sectional side view, corresponding with FIG. 3, showing afurther embodiment of the invention in which reinforcing bars areprovided in the cover,

FIG. 7 is a view, from above, of the air-bag arrangement of FIGS. 1 and2 with the upper cover removed to show the air-bag in position,

FIG. 8 is a view of an alternative embodiment of the invention,corresponding to FIG. 1,

FIG. 9 is an enlarged view of the punched-out attachment tongues presentin the embodiment of FIG. 8,

FIG. 10 is a side view of a further embodiment of the invention

FIG. 11 illustrates an air-bag arrangement which incorporates a loaddistribution element in accordance with the invention,

FIG. 12 shows the air-bag arrangement of FIG. 1 when inflated,

FIG. 13 is a view corresponding to FIG. 1 showing another embodiment ofthe invention,

FIG. 14 is a view corresponding to FIG. 2 showing another modifiedembodiment of the invention,

FIG. 15 is a partial sectional view of the embodiment of FIG. 1, and

FIG. 16 is a partial sectional view of another embodiment.

Referring to the accompanying drawings, a safety arrangement inaccordance with the present invention is intended to be mounted on thefloor pan of a motor vehicle in the foot-well immediately beneath and infront of the feet of an occupant of a vehicle. The illustratedarrangement may be covered by a carpet or the like, or may be formedintegrally with a carpet or the like.

Referring to FIG. 1 of the accompanying drawings, an air-bag unit 1 inaccordance with one aspect of the invention comprises a damp-proofsealed rectangular housing 2 which in this embodiment is made of aplastics material. The housing comprises a lower portion 3 having a base4 configured to lie on the floor pan of the motor vehicle in which theair-bag unit is mounted. In the illustrated embodiment the base 4comprises an initial flat substantially horizontal region 5, adapted tolie on a horizontal part of the foot-well, and has an upwardly inclinedregion 6, adapted to lie on an inclined region of the foot-well, forexample, beneath the accelerator brake (and clutch) pedals of thevehicle.

The lower portion 3 is connected, by means of side walls 7, to an uppercover 8. The upper cover 8 comprises two sections, namely a firsthorizontal section 9 which extends over the horizontal part 5 of thebase 4 of the housing, and a second, inclined section 10 which lies overthe inclined part 6 of the base. A foldable hinge-line 11 exists betweenthe first horizontal section 9 and the inclined section 10 of the uppercover 8.

The housing 2 thus presents a substantially planar horizontal portionadapted to be mounted on the horizontal part of the foot-well, and aninclined portion to be mounted on the inclined portion of the foot-well.Optionally the inclined portion may be provided with an axiallyextending slot 12 located adjacent one edge and extending towards thehinge-line 11, thus serving to divide the inclined portion into tworegions, namely region 13 of substantial size and region 14 of lessersize. The region 14 may be located on a foot-rest, if such a foot-restis provided within the vehicle.

The housing is mounted in position on the motor vehicle by means of tworestraining straps 15, 16 which extend from part of the first horizontalsection 9 of the upper cover 8 adjacent the hinge-line 11 downwardly,adjacent the sides of the housing, to fixed mounting points or the floorpan of the vehicle.

An air-bag, which will be described hereinafter, is contained within thehousing, and when the air-bag is inflated the upper cover 8 tends tomove upwardly relative to the lower portion 3 of the housing. Themovement of the initially horizontal first section 9 of the upper cover8 is restricted by the straps 15 and 16. The straps 15 and 16, as shownin FIG. 2, become tense, thus restricting the upward movement of theinitially horizontal first section 9 of the cover 8. This, in turn,restricts the upward movement of the hinge-line 11 and effects somecontrol upon the upward movement of the initially inclined section 10 ofthe upper cover 8. Thus even if the floor beneath the air-bagarrangement 1 becomes distorted or deformed, the cover 8 will only riseto a predetermined limited extent.

During inflation of the air-bag the side walls 7 of the housing eitherrupture or, alternatively, expand.

It is to be appreciated that the design of the housing is such that themaximum upward movement of the cover 8 will occur in the region of thehinge-line 11. Thus the edge of the initially horizontal section 9 ofthe cover 8 which is furthest from the hinge-line 11 is connected to thelower part 3 of the housing in such a way that this edge of the portionof the cover 8 will not move upwardly substantially on inflation of theair-bag. Similarly, the edge of the initially inclined section 10 of thecover which is furthest from the hinge-fine 11 is connected to the lowerpart 3 of the housing in such a way that this edge does not moveupwardly substantially upon inflation of the air-bag.

As a consequence, the portion of the upper cover 8 that initiallysupports the heels of the occupant, which will typically be a portion ofthe cover adjacent the hinge-line 11, is elevated, on inflation of theair-bag, to a greater extent than the portion of the cover that supportsthe forward part of the foot. This, it is believed, will serve toprevent the foot of the occupant being bent in an undesirable mannerupon inflation of the air-bag.

Thus the force applied to the under-part of the foot of the occupantwill be applied with a major part of the force being applied to the heelportion, and the heel portion is the part of the foot that is best ableto withstand this force. In order to further amplify this effect it isdesirable to have the portion of the cover located beneath the heels ofthe occupant somewhat stiffer, with a greater resistance to bending inthe axial direction, than the portion of the cover located beneath theforefoot of the occupant. Thus, as shown in FIG. 3 and FIG. 5, aplurality of reinforcing ribs 17 are provided on the under-surface ofthe inclined part 10 of the cover. Ribs 17 are also provided on theunder-surface of the horizontal section 9 of the cover. The reinforcingribs are spaced closely together in the region of each part 9, 10 of thecover adjacent the hinge-line 11. The reinforcing ribs extendtransversely, the reinforcing ribs 17 being spaced further apart in theportions of the originally planar section 9 and the originally inclinedsection 10 of the cover furthest from the hinge-line 11. The reinforcingribs thus provide maximum stiffness, i.e. maximum resistance to bending,in the region to be adjacent the heels of feet resting on the cover 8.

It is also to be appreciated that in this embodiment of the invention,because the reinforcing ribs extend transversely relative to the axis ofthe vehicle, the cover has substantial transverse strength, and resistsany tendency to bend in the transverse direction. Thus there is verylittle risk of the cover moving, on inflation of the air-bag, in such away that a twisting movement is applied to the foot, tending to twistthe foot about an axis which is aligned with the longitudinal axis ofthe vehicle.

Because there is a greater number of transverse ribs 17 beneath the heelof the foot rather than beneath the forward part of the foot, there isonly a minimal risk of the forward part of the foot being movedupwardly, relative to the heel, in an undesirable manner.

FIG. 4 illustrates a modified embodiment of the invention where, insteadof having a plurality of ribs 17, a single reinforcing rib 18 isprovided which provides reinforcement in the desired area. Thereinforcing rib 18 is positioned to be located directly beneath the heelof a foot resting on the housing 2.

FIG. 6 illustrates a further modified embodiment of the invention inwhich, instead of having reinforcing ribs, such as ribs 17 or 18,transversely extending reinforcing bars 19 are provided. The bars may beformed of metal or the like, and may be moulded integrally within thecover 8. The bars will be spaced apart in the same manner as the ribs 17as described above.

FIG. 7 illustrates the housing 2 that has been described above, with theupper cover removed. An air-bag 20 is shown provided within the housing.The air-bag 20 is provided with a gas flow duct 21 which is connected toan appropriate gas generator 22. The gas generator 22 is associated witha sensor 23 responsive to an impact or substantial deceleration of thevehicle. On sensing an impact or substantial deceleration, the sensoractivates the gas generator 22 which inflates the air-bag 20.

The air-bag 20 has a relatively large chamber 24 and a smaller chamber25 located beneath the initially inclined section 10 of the upper cover8, the chambers being on either side of the slot 12 that divides theinclined portion of the housing into the regions 13 and 14. The chambers24, 25 are connected to a plurality of smaller discrete chambers 26, 27,28, 29 which extend between the initially horizontal portion 9 of thecover 8 and the lower part 3 of the housing. Each of the discretechambers has a portion that will have a substantial diameter wheninflated located adjacent the hinge-line 11 and a tapering portionextending away from the hinge-line 11. It can be seen that the air-bagis provided with chambers which are configured so that, on inflation ofthe air-bag, the housing will adopt the position illustrated in FIG. 2and as described above.

In the embodiment as described, the air-bag may be glued or otherwisesecured to the housing so that the air-bag will be retained with anappropriate position within the housing. In the alternative embodimentillustrated with reference to FIGS. 8 and 9, the cover 8 is providedwith a plurality of securing tabs formed by cut-out tongues 30. Eachcut-out tongue 30 is constituted by forming a substantially “U”-shapedslot 31 within the material of the cover. Each tongue 30 may beconnected to an appropriate “loop” provided on the air-bag, to securethe air-bag in position relative to the cover. With the opposed ends ofthe air-bag fixed to the tongues 30 close to the end of the cover 8, andwith the straps 15, 16 securing parts of the first horizontal section 9of the upper cover 8 adjacent the hinge-line 11 to the floor pan of thevehicle, as the air-bag beneath the cover 8 inflates, so the opposedends of the cover will tend to rest against the floor pan of thevehicle.

Whilst in the above-described embodiments of the invention the coverforms part of a housing, it is to be understood that in a modifiedembodiment of the invention, as illustrated in FIG. 10, the cover maysimply be a cover that rests on the air-bag and which does not form partof the housing. FIG. 10 thus illustrates the floor pan 40 of a motorvehicle, the floor pan having a horizontal section 41 and an inclinedsection 42. Resting directly on the floor pan of the vehicle is anair-bag 43. The air-bag 43 is preferably a metal air-bag, since theair-bag will not be protected by a housing, since no housing is present.The air-bag may have a configuration similar to that of the air-bagshown in FIG. 7.

Resting on top of the air-bag is a cover 44, which is substantiallyidentical to the cover 8 described above. A strap 45 is provided, in theregion of a hinge-line 46 that is present in the middle of the cover, inorder to hold the cover in position.

The air-bag 43 will be associated with a gas generator which, in turn,is associated with a sensor.

It is to be appreciated that in an initial condition of the air-bag unitshown in FIG. 10, the cover 44 will present a first substantiallyhorizontal section 47 lying above the horizontal section 41 of the floorpan 40, and a second inclined section 48 lying above the inclinedsection 42 of the floor pan 40. On inflation of the air-bag 43, thecover will move to the position illustrated in FIG. 10, upward movementof the cover being restricted by the straps 45.

Referring to FIG. 11, an air-bag unit 51 comprises a damp-proof sealedrectangular housing 52 which in this embodiment is made of a plasticsmaterial. The housing comprises a lower portion 53 having a base 54configured to lie on the floor pan of the motor vehicle in which theunit is mounted. The base 54 comprises an initial flat substantiallyhorizontal region 55 adapted to lie on a horizontal part of thefoot-well, and has an upwardly inclined region 56 adapted to lie overthe inclined scuttle or toe-pan which is located in front of thehorizontal part of the floor-pan and beneath the accelerator, brake (andclutch) pedals of the vehicle.

The lower portion 53 is connected by means of side-walls 57 to an uppercover 58. The upper cover 58 comprises two sections, namely a firsthorizontal section 59 which lies over the horizontal part 55 of the base54 of the housing, and a second inclined section 60 in the form of aplate which lies over the inclined part 56 of the base. It is thisinclined section that constitutes the load distribution element 60 ofthe present invention in this embodiment.

A foldable hinge line 61 exists between the first horizontal section 59of the cover 58 and the part of the cover that constitutes the loaddistribution element 60. The hinge line 61 is relatively stiff, and mayjust be a line of mechanical weakness where the top cover 58 may bendwhen the air-bag within the housing 52 inflates.

The housing 52 thus presents a substantially planar horizontal portionto be mounted on the horizontal floor in the foot-well of a vehicle, andan inclined portion, the upper part of which is constituted by the loaddistribution element 60, to be mounted over the scuttle or toe-pan. Inthe illustrated embodiment there is an axially extending slot 62,extending parallel with the longitudinal axis of the vehicle in whichthe housing 52 is mounted, which is located adjacent one edge of thehousing 52 and which extends across the inclined portion of the housing52 towards the hinge line 61, thus serving to divide the inclinedportion into two regions, namely a region 63 of substantial size and aregion 64 of lesser size. The smaller region 64 may be located on afoot-rest, if such a foot-rest is provided in the vehicle.

The housing 52 is mounted on the motor vehicle by means of tworestraining straps 65, 66, which extend from part of the firsthorizontal section 59 of the upper cover 58 adjacent the hinge-line 61downwardly, adjacent the sides of the housing 52, to fixed mountingpoints on the floor pan of the vehicle.

An air-bag (shown in phantom in FIG. 12) is contained within the housing52, and when the air-bag is inflated, in response to a signal from asensor that detects an accident or an accident situation, the whole ofthe upper cover 58 tends to move upwardly relative to the rest of thehousing.

The load distribution element 60 is provided with a reinforced region 67in which the strength or stiffness of the plate that forms the loaddistribution element is enhanced. The strength or stiffness is theproperty of the plate that determines how easily the plate will bend.The reinforced region includes a first rectangular area 68 which islocated at the base of the region 64 and adjacent the hinge-line 61.Thus the rectangular area 68 is adapted to lie under the heel of anoccupant, and in the described embodiment is located to lie under theheel of a foot that is not ordinarily operating a pedal, such as theleft foot of the driver. Conjoined with the area 68 is a further area 69of the reinforcement in the form of an elongate strip of reinforcementthat forms the side border or edge of the region 64. Thus the reinforcedregion is made up of the two conjoined areas 68 and 69. The reinforcedregion 67 may lie adjacent a further small reinforced region provided inthe first section 59 of the upper cover 58 adjacent the hinge-line 61identified as the region 70.

The rest of the region 64, which is the region adapted to lie under theleft foot of the occupant of the vehicle in the described embodiment, isan area 71 of the load distribution element which is weaker, orreinforced to a lesser extent, than the area 72 which makes up the restof the load distribution element 60. Thus the area 72 may be formed froma plate of a predetermined strength, and the area 71 may be made to beof less than the predetermined strength, for example by being madethinner so that is has strength less than the predetermined strength.The reinforced region 67 has a strength greater than the predeterminedstrength.

When the air-bag is inflated, and the upper cover 58 moves upwardly, themovement of the first initially horizontal section 59 of the cover 58 isrestricted by the straps 65 and 66. As shown in FIG. 2, the straps 65,66 become tightened, and then prevent further upward movement of theinitially horizontal section 59 of the cover 58. This preventscontinuing upward movement of the hinge-line 61, and effects somecontrol on the movement of the load distribution element 60 of theinvention. Thus, even if the floor beneath the housing 52 is buckled,the cover 58 will only rise to a predetermined extent.

During inflation of the air-bag the side walls 57 of the housing eitherrupture or expand.

The reinforced region 67 and the relatively weak area 71 are, in thedescribed embodiment, dimensioned and located so that the housing 52 maybe used in a motor vehicle where there is a risk that, in a frontalimpact, there may be an intrusion into the vehicle cabin, through thescuttle or toe-pan in the region just to the right of the foot rest.Thus this embodiment may be used when it is expected that there may bean intrusion into the cabin of the vehicle in the region of the slot 62.If there is an intrusion in this region the inclined region 56 of thebase 54 of the housing 52 will move towards the right hand side of theregion 64 bounded by the slot 62. This may tend to rotate the uppersurface of the region 64 of the load distribution element so as toimpart inversion to a left foot of an occupant resting on this region ofthe load distribution element. The reinforced region 67, and inparticular the area 69 that forms the border of the region 64 lyingunder the left foot of the occupant will keep that area in a desiredposition, thus preventing undesired movement of that area towards thefoot of the occupant. However, because the relatively weak area 71 islocated beneath the right hand side of the left foot, the loaddistribution element 60 will yield in the area 71, so that the foot issubjected to a minimum of inversion, thus minimising the risk of injury.The element 60 thus acts to distribute the downward load applied to theelement by the foot of the occupant, and also the upward load applied tothe element by an item intruding into the cabin of the vehicle.

The major part of the force applied to the under-part of the foot of theoccupant will be applied in the region of the heel, and the heel is thepart of the foot that is most able to withstand this force. In order toamplify this effect in embodiments of this invention the area of theload distribution element to be located under the heel of at least onefoot is reinforced. The reinforcing may be such that the loaddistribution element is very resistant to bending about an axis parallelwith the longitudinal axis of the vehicle in which the housing 52 ismounted, and, as will be described below, the reinforcing may comprisetransversely extending ribs. The advantage of such ribs is that, byusing an appropriate design, the load distribution element 60 may bevery resistant to bending about an axis parallel with the axis of thevehicle and less resistant to bending about a transverse axis. However,the reinforcing in the region 67 may be simply a thickening of the platethe forms the load distribution element 60.

FIG. 13 illustrates a modified embodiment of the invention in which theload distribution element 60 is provided with a U-shaped reinforcedregion 73. The region 73 has a rectangular area 74 extending the wholewidth of the load distribution element 60 adjacent the hinge-line 61, tolie beneath the heels of both feet of the occupant of the vehicle. Thereare two areas 75, 76 which are conjoined with the area 74 which extendadjacent the two side edges of the load distribution element 60, andthere are rectangular areas 77 and 78 where the load distributionelement has a strength that is less than that of the rest of theelement, the areas 77 and 78 being located adjacent the areas 75, 76.

An arrangement as shown in FIG. 13 may provide protection for both feetof a vehicle occupant, especially if there is an intrusion into thevehicle cabin at a point between the feet of the occupant.

FIG. 14 illustrates another embodiment in which there is no slot 62 andthe load distribution element is provided with a reinforced region 80constituted by a first rectangular area 81 to be located beneath theheel of the left foot of an occupant, and a second area 82, separatedfrom the area 81, which extends diagonally across the load distributionelement from the lower right hand corner to the upper left hand cornerin the orientation illustrated.

FIG. 15 illustrates part of the reinforced region 67 of the embodimentof FIGS. 11 and 12 showing that the reinforcing is constituted by aplurality of reinforcing ribs 83 provided on the under-surface of theload distribution element 60. The reinforcing ribs 83 are spacedrelatively closely together in the region 84 which is close to the hingeline 61 and are spaced further apart in the region 85 which is moreremote from the hinge line 61. Thus the strength of the reinforcing inthe reinforced region 67 may be reduced with increasing distance fromthe hinge line 61. Also the strength of the reinforcing may vary atdifferent points across the width of the load distribution element asshown in the drawings. Thus, the reinforcing may, for example, be weakerin a central region of the load distribution element than at the edges.

In a simple embodiment of the invention the reinforcing of thereinforced region may be constituted by a relatively wide rib 86provided on the under-surface of the plate forming the load distributionelement, as shown in FIG. 16. The reinforced region may comprise simplya region to be located beneath the heel of one foot of the occupant, butmay include additional areas as described above to provide enhancedprotection for a single foot, or protection for both feet. A loaddistribution element of the type described above may be provided notonly for the driver of a vehicle, but also for a front-seat passenger.

Whilst in the embodiment of FIGS. 11 to 16, a load distribution elementis described with reference to an air-bag arrangement it is to beunderstood, that the load distribution element may simply be located on,or formed with, the floor of the vehicle, or may be mounted on the floorwith some form of padding between the floor and the load distributionelement.

In the present Specification “comprise” means “includes or consists of”and “comprising” means “including or consisting of”.

The features disclosed in the foregoing description, or the followingClaims, or the accompanying drawings, expressed in their specific formsor in terms of a means for performing the disclosed function, or amethod or process for attaining the disclosed result, as appropriate,may, separately, or in any combination of such features, be utilised forrealising the invention in diverse forms thereof.

What is claimed is:
 1. An air-bag unit adapted to be positioned on thefloor pan of a motor vehicle in the foot-well, to be located beneath thefeet of an occupant of the vehicle, the air-bag unit having an air-bag,and having an upper cover located above the air-bag, the unit being suchthat on inflation of the air-bag the cover is lifted from its initialposition to an elevated position the upper cove comprising two sectionsinter-connected by a hinge-line, the two sections being adapted suchthat on inflation of the air-bag the part of the cover adjacent thehinge-line is elevated to a greater extent than the portions of thecover which are remote from the hinge-line, wherein the cover comprisestwo sections, in the form of a first section adapted to be substantiallyhorizontal and the second section adapted to be inclined, the air-baglying under the second section presenting a relatively large chamber,and the air-bag lying under first section presenting a plurality ofseparate chambers.
 2. A unit according to claim 1 wherein a pair ofattachment elements are provided, the attachment elements each beingconnected to one part of the upper cover and being adapted to beconnected to part of the motor vehicle to restrict upward movement ofthe said part of the cover.
 3. A unit according to claim 1 wherein eachof the separate chambers is a tapering chamber.
 4. A unit according toclaim 1 wherein the dined section of the cover is provided with a slitseparating the inclined section into two regions, one region beingadapted to lie on a foot-rest.
 5. A unit according to claim 1 whereinthe cover is provided with reinforcing means, the reinforcing meansextending transversely of the cover.
 6. A unit according to claim 5wherein the reinforcing means comprise thickened portions of the cover.7. A unit according to claim 5 wherein the reinforcing means compriseintegral elements of a reinforcing material located within the cover. 8.A unit according to claim 1 wherein the cover is provided withreinforcing means to resist deformation of the cover, there being ore orstronger reinforcing means in the region of the cover adapted to lieunder the heel of an occupant of the vehicle than in other areas of thecover.
 9. A unit according to claim 8 wherein the reinforcing meansextend transversely of the cover.
 10. A unit according to claim 1wherein the air-bag is secured to the cover by adhesive.
 11. A unitaccording to claim 1 wherein the cover is provided with integrallyformed tongues, the air-bag being connected to the cover by means ofelements provided on the air-bag which engage the said tongues.
 12. Aunit according to claim 1 wherein the cover forms part of a housing thatcontains the air-bag.
 13. A unit according to claim 1 wherein the coverrests on the airbag.
 14. An air-bag unit adapted to be positioned on thefloor pan of a motor vehicle in the foot-well, to be located beneath thefeet of an occupant of the vehicle, the air-bag unit having an air-bag,and having an upper cover located above the air-bag, the unit being suchthat on inflation of the air-bag the upper cover is lifted from itsinitial position to an elevated position, the upper cover being providedwith reinforcing means, the reinforcing means extending transversely ofthe cover to provide the cover with substantial transverse rigidity,wherein the cover is provided with integrally formed tongues, theair-bag being connected to the cover by means of elements provided onthe air-bag which engage the said tongues.
 15. A unit according to claim14 wherein the reinforcing means comprise thickened portions of thecover.
 16. A unit according to claim 14 wherein the reinforcing meanscomprise integral elements of a reinforcing material located within thecover.
 17. A unit according to claim 14 wherein the air-bag is securedto the cover by adhesive.
 18. A unit according to claim 14 wherein thecover forms part of a housing that contains the air-bag.
 19. A unitaccording to claim 14 wherein the cover rests on the air-bag.
 20. Anair-bag unit adapted to be positioned on the floor pan of a motorvehicle the foot-well, to be located beneath the feet of an occupant ofthe vehicle, the air-bag unit having an air-bag, the unit having anupper cover located above the air-bag, the unit being such that oninflation of the air-bag the upper cover is lifted from its initialposition to an elevated position, the upper cover being provided withreinforcing means to resist deformation of the cover, there being moreor stronger reinforcing means in the region of the cover adapted to lieunder the heel of an occupant of the vehicle than in other areas of thecover, wherein the cover is provided with integrally formed tongues, theair-bag being connected to the cover by means of elements provided onthe air-bag which engage the said tongues.
 21. A unit according to claim20 wherein the air-bag is of metal.
 22. A unit according to claim 20wherein the reinforcing means comprise thickened portions of the cover.23. A unit according to claim 20 wherein the reinforcing means compriseintegral elements of a reinforcing material located within the cover.24. A unit according to claim 20 wherein the air-bag is secured to thecover by adhesive.
 25. A unit according to claim 20 wherein the coverforms part of a housing that contains the air-bag.
 26. A unit accordingto claim 20 wherein the cover rests on the air-bag.